Slice level signaling in video bitstreams that include subpictures

Abstract

An example method of video processing includes performing a conversion between a video comprising one or more pictures and a bitstream representation of the video. The bitstream representation is required to conform to a format rule that specifies that each picture is coded as one or more slices. The format rule prohibits samples in a picture from not being covered by any of the one or more slices.

The invention claimed is: 
     
       1. A method of video processing, comprising:
 partitioning, for a conversion between a picture of a video and a bitstream of the video, the picture into one or more slices and into one or more sub-pictures according to a requirement of bitstream conformance; and 
 performing the conversion at least based on the partitioning, 
 wherein the requirement of bitstream conformance specifies that a union of the one or more slices resulted from the partitioning of the picture cover a whole picture, 
 wherein the requirement of bitstream conformance further specifies that a union of the one or more sub-pictures resulted from the partitioning of the picture cover the whole picture, and 
 wherein a slice of the picture overlaps with at most one sub-picture of the picture. 
 
     
     
       2. The method of  claim 1 , wherein a first syntax element is included in the bitstream to indicate whether the one or more slices have a rectangular shape. 
     
     
       3. The method of  claim 1 , wherein a sub-picture of the one or more sub-pictures is partitioned into one or more slices,
 wherein the requirement of bitstream conformance further specifies that a union of the one or more slices resulted from the partitioning of the one or more sub-pictures cover a whole sub-picture. 
 
     
     
       4. The method of  claim 1 , wherein a tile of the picture overlaps with at most one sub-picture of the picture. 
     
     
       5. The method of  claim 1 , wherein the conversion includes encoding the picture of the video into the bitstream. 
     
     
       6. The method of  claim 1 , wherein the conversion includes decoding the picture of the video from the bitstream. 
     
     
       7. An apparatus for processing video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:
 partition, for a conversion between a picture of a video and a bitstream of the video, the picture into one or more slices and into one or more sub-pictures according to a requirement of bitstream conformance; and 
 perform the conversion at least based on the partitioning, 
 wherein the requirement of bitstream conformance specifies that a union of the one or more slices resulted from the partitioning of the picture cover a whole picture, 
 wherein the requirement of bitstream conformance further specifies that a union of the one or more sub-pictures resulted from the partitioning of the picture cover the whole picture, and 
 wherein a slice of the picture overlaps with at most one sub-picture of the picture. 
 
     
     
       8. The apparatus of  claim 7 , wherein a first syntax element is included in the bitstream to indicate whether the one or more slices have a rectangular shape. 
     
     
       9. The apparatus of  claim 7 , wherein a sub-picture of the one or more sub-pictures is partitioned into one or more slices,
 wherein the requirement of bitstream conformance further specifies that a union of the one or more slices resulted from the partitioning of the one or more sub-pictures cover a whole sub-picture. 
 
     
     
       10. The apparatus of  claim 7 , wherein a tile of the picture overlaps with at most one sub-picture of the picture. 
     
     
       11. A non-transitory computer-readable storage medium storing instructions that cause a processor to:
 partition, for a conversion between a picture of a video and a bitstream of the video, the picture into one or more slices and into one or more sub-pictures according to a requirement of bitstream conformance; and 
 perform the conversion at least based on the partitioning, 
 wherein the requirement of bitstream conformance specifies that a union of the one or more slices resulted from the partitioning of the picture cover a whole picture, 
 wherein the requirement of bitstream conformance further specifies that a union of the one or more sub-pictures resulted from the partitioning of the picture cover the whole picture, and 
 wherein a slice of the picture overlaps with at most one sub-picture of the picture. 
 
     
     
       12. The non-transitory computer-readable storage medium of  claim 11 , wherein a first syntax element is included in the bitstream to indicate whether the one or more slices have a rectangular shape. 
     
     
       13. The non-transitory computer-readable storage medium of  claim 11 , wherein a sub-picture of the one or more sub-pictures is partitioned into one or more slices,
 wherein the requirement of bitstream conformance further specifies that a union of the one or more slices resulted from the partitioning of the one or more sub-pictures cover a whole sub-picture. 
 
     
     
       14. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:
 partitioning, for a picture of a video, the picture into one or more slices and into one or more sub-pictures according to a requirement of bitstream conformance; and 
 generating the bitstream at least based on the partitioning, 
 wherein the requirement of bitstream conformance specifies that a union of the one or more slices resulted from the partitioning of the picture cover a whole picture, 
 wherein the requirement of bitstream conformance further specifies that a union of the one or more sub-pictures resulted from the partitioning of the picture cover the whole picture, 
 wherein a slice of the picture overlaps with at most one sub-picture of the picture. 
 
     
     
       15. The apparatus of  claim 7 , wherein the conversion includes encoding the picture of the video into the bitstream. 
     
     
       16. The apparatus of  claim 7 , wherein the conversion includes decoding the picture of the video from the bitstream. 
     
     
       17. The non-transitory computer-readable storage medium of  claim 11 , wherein a tile of the picture overlaps with at most one sub-picture of the picture. 
     
     
       18. The non-transitory computer-readable recording medium of  claim 14 , wherein a first syntax element is included in the bitstream to indicate whether the one or more slices have a rectangular shape. 
     
     
       19. The non-transitory computer-readable recording medium of  claim 14 , wherein a sub-picture of the one or more sub-pictures is partitioned into one or more slices,
 wherein the requirement of bitstream conformance further specifies that a union of the one or more slices resulted from the partitioning of the one or more sub-pictures cover a whole sub-picture. 
 
     
     
       20. The non-transitory computer-readable recording medium of  claim 14 , wherein a tile of the picture overlaps with at most one sub-picture of the picture.